1. Field of the Invention
The present invention relates to a cutter block in drum-disk or annular form for chipping equipment for removing generally flat and/or relatively long particles of grown wood for producing excelsior, preliminary material for particle board, and the like, essentially including a block body having at least one longitudinally straight or helical recess in the surface region; in this recess, a part connected to a knife is guided by retaining means in a manner protected against radial displacement, and the part can be pressed by a centrifugal wedge or chuck against a side wall of the recess.
The invention also relates to a discontinuous or plural edge knife or solid blade knife for cutter spindle chippers for removing generally flat and/or relatively long particles of grown wood for producing excelsior, preliminary material for particle board and the like, essentially including a base body and, leaving intermediate regions with end faces free in the longitudinal direction, cutting regions protruding laterally from these end faces and having cutting edges.
2. Description of Background and Material Information
In the production of particle board (also called wood fiber board), generally flat and/or elongated particles or chips of wood are joined together using adhesives such as resins, glues and the like. This joining is made or initiated between spaced-apart, optionally moving pressure faces under pressure. To obtain the particles, wood is chipped or chips of slight thickness are removed from the wood and subjected to further processing. The chipping or removal is done with cutter blocks, which have knives with optionally discontinuous blades in the region of their surface. Such knives or chipping knives are made of knife steel or tool steel that suitably holds an edge, typically having a thickness of 5 millimeters (mm) or more and being able to be resharpened many times by grinding down the beveled face. FIG. 1 illustrates the known prior art.
For the purpose of resharpening the knife edge, as shown in FIG. 1, the knife 5 can be readjusted radially of the cutter block 1 and fixed to a guide part 4 by connecting means, such as cap screws 41, in the slit region. The greatest possible knife thickness is chosen, on the one hand, to achieve stable anchoring of the blade part by means of at least five thread courses, for instance and, on the other hand, to keep vibration of the blade during chip removal as slight as possible, so that chip breakage and hence the generation of undesired fines will be minimized.
In this kind of cutter block for chipping, having a multiple edge (or discontinuous blade) knife or solid blade knife embodiment in which the thickness of the blade part is significant, re-grinding to form a sharp knife edge can be done many times, and only slight amounts of fines are produced in the removal of the wood. Nevertheless, the precise radial adjustment of the knife in the block body so as to be secure during operation, and the production of the blade part itself, are costly in time and money and require long chipper set-up times, as well as involving expense for procurement and warehousing.